Due to their rarity and unique visual properties, nearly all coloured gemstones sold at fine jewellers, including Blue Nile,
are enhanced using various techniques. Many of these techniques have been used for centuries. Coloured gemstones that have not
been enhanced are very rare and command extravagant prices.

Our white and fancy-colour diamonds are not enhanced in any way, other than normal cutting and polishing. Black diamond fashion jewellery contains natural diamonds that have been treated to create the unique black colour.

Coloured Gemstone Enhancement Processes

There are many methods of enhancing coloured gemstones. We describe
the most common enhancements below. For more information on coloured gemstone enhancements, see the American Gem Trade Association's
Gemstone Information Manual.

Heat Treatment

The application of heat to enhance the colour and/or clarity of gemstones has been a common practice around the globe for centuries. It is part of the standard polishing and finishing process for many coloured gemstones. As such, it is accepted by the jewellery industry and the American Gem Trade Association. The enhanced colour and/or clarity of heat-treated gemstones is permanent.

Infusion

The filling of a gem material with an oil, wax, glass, resin or other material, coloured or colourless, to improve appearance. This process began centuries ago by gemstone merchants who found that immersing emeralds in oil or waxes made them look clearer to the unaided eye. This practice continues today with many coloured gemstones.

Coating

The use of wax, resin or oil applied to the exterior of a porous coloured gemstone to protect the natural substance, and to improve sturdiness and appearance.

Bleaching

The application of chemicals or other elements to lighten or enhance colour consistency.

Dyeing

The act of adding coloring agents so that they permeate a coloured gemstone to enhance or alter colour.

Irradiation

The alteration of a gemstone's colour through the use of radiation. This is often followed by a heating process. The enhanced colour of irradiated gemstones is permanent.

New and Future Technologies

Techniques for enhancing coloured gemstones, either detectable or otherwise, are continually being developed. These may be difficult, or in rare cases, impossible to detect, even for the most sophisticated laboratory. Blue Nile will continue to work with industry groups and gemmological experts who are committed to the identification and disclosure of new and future techniques in order to maintain our stringent quality standards.

Basic Gemstone Care

While gemstones are durable, they require varying levels of care. For example, some gemstones are especially
vulnerable to household chemicals and temperature changes. Cleaning gemstones presents special challenges.
While many gemstones should be cared for by following our basic care guidelines below, please refer to our
Gemstone and Pearl Care and Enhancement Overview to understand the care requirements for your specific stone. If
you still have questions, please contact Blue Nile customer service.

Cleaning

After removing your gemstone jewellery, clean it by following the directions on a non-abrasive jewellery cleaner. Make sure that the jewellery cleaner specifies that it is safe to use with your gemstone. Use a soft cloth to remove any remaining dirt or other residue.

Storing

Store your gemstone jewellery in a lined case or a soft cloth, so the gems do not touch each other or parts of other jewellery. Gemstones are harder than gold, silver, or platinum and can scratch the surfaces of your other fine jewellery if they are not kept separate.

Wear

While it's true that gemstones such as ruby and sapphire are second only to diamond on the hardness scale, it is not a measurement of their indestructibility. It means that these gemstones are able to resist scratching almost as well as a diamond. Abrasive surfaces, harsh chemicals, and sharp blows can damage even the hardest gem. Your gemstone jewellery should be the last thing you put on when getting dressed and the first thing you take off at the end of the night. Store your gemstones carefully and they will be enjoyed for generations.